Automotive Gasket Compounds

Gasket makers, threadlockers and structural repair compounds for automotive work: 3M weatherstrip and headliner adhesives and plastic emblem adhesive, DAP and Permatex silicone gasket sealant, Devcon metal patch and threadlocker gel, and J-B Weld epoxies including high-heat grades. Silicone RTV gasket maker and a cut gasket are not interchangeable — RTV needs a clean, dry, oil-free flange and a cure period before the joint sees pressure. Threadlocker strength is what decides whether the fastener can come apart again: medium strength releases with hand tools, high strength generally needs heat. Check the temperature rating before you buy an epoxy for anything near an exhaust or a manifold; standard grades soften well below where high-heat grades hold.